CL-Yacc is a LALR(1) parser generator for Common Lisp, similar in spirit to AT&T Yacc, Berkeley Yacc, GNU Bison, Zebu, lalr.cl or lalr.scm.CL-Yacc uses the algorithm due to Aho and Ullman, which is the one also used by AT&T Yacc, Berkeley Yacc and Zebu. It does not use the faster algorithm due to DeRemer and Pennello, which is used by Bison and lalr.scm (not to be confused with lalr.cl).While CL-Yacc has undergone no systematic testing, I use it for compiling a grammar for a superset of « C » (over 400 productions) that routinely parses thousands of lines of « C » code.